Abstract：
Dedifferentiated/undifferentiated melanoma (DM/UM) is a distinct subtype of malignant melanoma that tends to lose all melanocytic markers of differentiation. DM/UM pose major diagnostic challenges as they could be easily confused with UM sarcoma or carcinoma, thus necessitating the use of molecular studies such as Next Generation Sequencing (NGS) for detecting melanoma-compatible mutations to confirm such diagnosis. The capability of performing NGS molecular studies on small biopsy material with confirmation of adequacy via rapid on-site evaluation (ROSE) has tremendous value in diagnosing DM/UM. Herein, we present the first reported case of metastatic DM/UM to the gall bladder arising in a 60-year-old female with a prior history of right knee melanoma. We also shed light on the cytomorphology of DM/UM, review the literature on such a challenging entity, and emphasize the crucial role of molecular testing in their diagnosis.
摘要：
去分化/未分化黑素瘤(DM/UM)是恶性黑素瘤的独特亚型,其倾向于失去分化的所有黑素细胞标志物。DM/UM构成了主要的诊断挑战，因为它们很容易与UM肉瘤或癌混淆。因此，有必要使用分子研究，如下一代测序（NGS）来检测黑色素瘤相容性突变，以确认这种诊断。通过快速现场评估（ROSE）对小型活检材料进行NGS分子研究并确认其充分性的能力在诊断DM/UM中具有巨大价值。在这里，我们介绍了首例报道的转移性DM/UM至胆囊的病例，该病例发生于一名60岁女性，有右膝黑色素瘤病史。我们还阐明了DM/UM的细胞形态学，回顾关于这样一个具有挑战性的实体的文献，并强调分子检测在其诊断中的关键作用。
